I have submitted a full building regulations application for a two storey side and rear extension to a substantial semi-detached property in Shepperton, Surrey. Once a planning application has been submitted and approved it's important to convert these drawings in to a legal set of construction drawings.
Building Regulation Drawings are a set of detailed drawings and construction details that are submitted to the local building control department and go into much more detail than the planning application drawings. They incorporate structural information from the engineer, thermal insulation calculations and proof of full compliance with all relevant sections of the Building Regulations. They also include enough information for a contractor to accurately price as well as detailed set of construction specification notes and full product specific information to allow the contractor to price and ultimately build from.
Not many architects are able to do these drawings for you, so it is always best to employ someone who can do both the planning and building regs drawings to prevent messing around with two professional appointments!
A couple of example drawings below and as you can see, very detailed:-